Electrical components require electrical power to operate and power supplies of one kind or another typically serve in those regards. Unfortunately electrical faults of various kinds can and do occur from time to time that interrupt the provision of this electrical power or that otherwise present operational difficulties and concerns. As one exemplary concern in these regards, the power supply itself may be damaged when such a fault occurs.
Some power supplies employ output protection that serve to protect the power supply when the power supply output feeds a low-impedance fault. This can comprise, for example, continuing to supply a maximum rated output current but at a reduced output voltage when a low-impedance fault occurs on, for example, a printed circuit board that represents the load. Unfortunately, while such an approach will typically succeed in protecting the power supply, the load itself may experience damage.
Furthermore, such an approach will often not succeed in detecting a high-impedance fault. Such a circumstance can also lead to a build-up of unwanted heat. This heat, of course, typically represents wasted energy and reduces the efficiency of the overall electrical system. Such heat, in turn, can also cause the resistance of the fault to decrease and hence create even more heat in an unwanted cycle sometimes referred to as thermal runaway.
Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. Certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. The terms and expressions used herein have the ordinary technical meaning as is accorded to such terms and expressions by persons skilled in the technical field as set forth above except where different specific meanings have otherwise been set forth herein.